Carriage drive power control



Aug. 4, 1953 w, AG 2,647,609

CARRIAGE DRIVE POWER CONTROL.

Filed Dec. 28. 1950 INVENTOR.

WALTER r SAGNER film 47% A TTORNE V Patented Aug. 4, 1953 CARRIAGE DRIVE POWER CONTROL Walter T. S-agner, West Hartford, Conn., assignor to Underwood Corporation, New York, N. Y., a corporation of Delaware Application December 28, 1950, Serial No. 203,068

12 Claims.

This invention relates to mechanisms in type- Writers or other office machines for returning a carriage by motor power, and more particularly pertains to devices for controlling a motor return drive to obtain carriage return runs to accurate predetermined positions.

In typewriting machines the carriage must be power-returned reliably to settle in the exact letter-feed position corresponding to the begin-- ning of a new writing line. In most conventional constructions the disabling of the power-return mechanism entails the opening of a drive clutch against considerable opposition, and also the return movement through the final space is not only too short to assure sufiicient clutch opening movement, but if the carriage return run is short, the carriage also moves with too little momentum to furnish a reliably active clutch opening force. In machines having a fine letter-feed pitch, the difficulty is accentuated because the clutch opening action must ensue in a very small movement of the carriage if the carriage is to settle in the exact desired letter-feed position. Entering into the problem is also the yield and necessary work ing play in the mechanism for transmitting opening action to the drive clutch.

For efiecting more reliably carriage return terminations it has become known to employ power devices called into operation at the end of power returns, but such devices have been of complex nature or they operated harshly, and in some cases a power-actuated carriage return draw band served to impart the clutch opening motion and for this was subjected to increased strain and wear.

Towards overcoming the stated difficulties and deficiencies present in prior devices, it is an object of the invention to provide simple, accurately and reliably effective means employing motor power to disable a carriage return mechanism responsively to the carriage reaching the desired return position.

A further object of the invention is to provide eflicient power return means for a carriage, including a reliably controlled easily active mechanism operating at the conclusion of each return run under power supplied by the power return drive.

It is a more specific object of the invention to provide in connection. with power return mechanism embodying a carriage return draw band, eflicient, easily active means to disable the power return mechanism by a straightening action of said draw band, reliably controlled to ensue at the arrival of the carriage in the return 2 position while subjecting the draw band and other mechanism to a minimum of strain, wear and shock.

It is also an object of the invention to provide in association with a normally disabled power return drive for a carriage, efiicient control devices whereby such return drive is enabled under power of a spring responsive to a tripping action and whereby the drive is opened efliciently responsive to arrival of the carriage in return position by power action automatically and reliably supplied at the proper time by the carriage return drive.

In conjunction with all the above stated objects it is a further object to provide for eflicient line spacing of a paper supporting device provided on the carriage, and as an initial event in each activation of the power carriage return means before any power return movement of the carriage commences.

Many other objects and features of the invention will be apparent upon consideration of the detailed description which follows, as such description is read in the light of the accompanying drawings, but it is to be understood that the invention is capable of embodiment other than that specifically described.

General reference is had to the power return mechanism shown in the patent to Helmond, No. 2,262,676, dated November 11, 1941, over which the present invention is an improvement.

Referring to the drawings:

Figure 1 is a front sectional elevation illustrating a power return drive for a typewriter carriage, and controlling mechanism for said return drive, all in normal, idle condition,

Figure 2 is a fragmentary front perspective view of a line spacing device which is the same as in said patent and which is provided at the left end of the typewriter carriage,

Figure 3 is a front elevation similar to Figure 1 but the power return mechanism for the carriage is in the process of being disabled by the motor power as a result of the carriage having reached return position, and

Figure 4 is a side elevation of a carriage return enabling trip mechanism including a schematically represented carriage return key lever.

Referring now more particularly to Figure l, a fragmentarily illustrated typewriter carriage is designated by the numeral l9 and includes a left and a right carriage end I! rising from a usual rail 12, the latter being guided in a conventional manner between a front trackway l3 tending lengthwise thereof at the rear a bar ll supporting a line-end margin stop 18 and a re turn limiting margin stop [9.

A carriage feed spring, not shown, carriage if! in letter-feed direction; leftwardly and a usual letter-feed escapement, also not shown, is in control over the carriage as in conventional typewriters.

by the two margin stops l8 and I9 in'con'junction with counterstop means which in the structure shown may be regardedto comprise in upright counterstop arm 2%, and another arfrf'zl the purposeof which will be explai'ried'f later, both said arms 21] and 2! rising from'below-the housing through the perforation 22 provided in'a top plate 23 of the housing [6. Thef'counte'rstop arm 29 has at its lower end a slot 26a for mounting it on a frame-supported pin 28: Spring means 26b urge and hold the cou'nterstop'arm 2.8 upwardly to the limit established b'y the lower end of the slot 26c, and rightwardly tothe dinner the perforation 22 in the top plate 23. Towards the end of typing a line, the line-end margin stop it engages and displaces the counterstop arm 22 leftwardly in the perforation 22. In turn the stop arm 28 operates a lever indicated at 29 of a conventional line-end lock mechanismfor the typing instruinentalities which'may be in the form shown in the patent to Yaeger, No. 2,362,229, dated November '7, 1944. If after the line-end lock mechanism becomes effective it is desired to type beyond the margin'fthere' is operated. a usual line-end lock releasin mechanism which acts on the counterstop' arm. to move it downwardly below the range of both margin stops and of which only a lever 29a .for downward action on a pin of the arm 29 is'show'n. The other arm 2i of the counterstop means stands normally at'the left limit in the perforation 22 and. reaches downwardly alongtlie counterstop arm 28 for pivotal support thereon at 21c.

The return. drive for the carriage is the same as in the stated patent to Helinond and comprises a gear 264 and a clutch member fast on a shaft 26, the gear fi l, and. therefore the clutchmember 25, being continuously motor. driven while the machine is in use. Adjacent the clutch. member 25 on the shaft 26, but normallyseparated therefrom and thus not turning, is another clutch member 2? as seen in Figurel. .The clutch members 25 and 2t have clutch teeth which face axially of the shaft littowards each otherand are normally separated. The clutch member 2i is in the form of a sleeveloosely mounted on the shaft and has an annular groove 30 for accommodation of a conventional clutch closing fork (ii. A carriage return draw band drum 32 is freely rotatable on the shaft 26-but axially stationary. The clutch member 2 is connected with drum 32 for axial shiftrelative thereto and rotation therewith by provision of splines 33 which extend from said clutchinember 2'! into perforations in the draw band drum 32 Under constant urge of a light clock-type spring 3 5 contained in a shell 35, the drum 32 keeps a draw band extending therefrom to a The normal opposite range of line travel of the carriage is established line spacing mechanism 39 on the carriage, under constant light tension to take up slack. The clutch controlling fork 3i is part of a rocking structure including also an arm 3?, and this rocking structure, by means of a fairly strong spr'ngifi [in Figures 1 and3, is constantly urged clockwi'seto urge engagement of the clutch member 21 with the clutch member 25. Normally, however, as seen in Figure l, the rocking structure 31, 3] is held in an open clutch position by a control arm 40 which has pivotal supflth frame'as at M and has a link conne. 1o n 42 fwi'th the arm 3?, the said control arm as'shown in Figure 4 being normally retained bra-latch 43 against upward, clutch closing movement.

are draw band 36 leads from the winding drum 32 upwardly over an idler sheave a l and from there ,leftwardlyin a bend around the underside of a pulley 45, first over an idler pulley 46 .and'then, overan idler pulley i? and finally onto a small drum 48 which is rotatively supportedon the leftcarriage end H and comprises a part of the aforestated line spacing device 39. Referring to Figure 2 the line spacing device comprises further a bevel pinion 5c unitarily rotatablewith the v drum l8 and meshing with a bevellgearsector 5! which is pivotally supported on the carriage. as at 52. Said sector ill has integral therewith a cam 53 on which there bears afollowerroll 54. Said follower roll lid is on a usual spring-restored lever 55 which carries a line spacepawlfii for line-feeding engagement withausual toothed line space wheel 5?, the latter being fast ona platen shaft 58. A spring 50 is strong ,enough relatively to the draw band winding spring iidto cause the sector 5! normally to oCcupythe position seen in Figure 2 wherein a part of the sector engages a stop pin (it. suchnormal position of the sector 5! someofthe draw bandtii is wound on the drum 68, .it being understood that an end of the draw band has an anchorage on such drum. Whenever the carriage return drive is rendered active in a manner tobbe explained hereinafter, the draw band, before picking up the carriage will turnthe ,drum'A'S of the line spacing device 339, for the, cam 53ft'o act on the roller 54 and to cause ,aline spacing operation. The movement of the sector. is limited by engagement of a pin 62',with apart of the carriage end, and following such ehgag'ement'the draw band 3% picks up the carriage l0 and moves it in return direction.

The pulley d5 about which the draw band is led in a bend is mounted on an arm 86 of a carriage return Shut-off lever which is pivoted at 69 and includes another arm li'l having a roller 68 for carriagereturn shut-off descent on the arm 40 which has connection with the clutch control fork 3 I. A spring iii having connection with the arm 56 is strong enough with respect to the draw band winding spring 34 to cause the lever to rest normally in a clockwise direction against a pin '52. v The carriage return drive clutch 25, 2? is closealole under control of a carriage return key schematically represented at "E5 in Figure 4 to cause a line-spacing operation followed by a returninotion of the carriage to the limit afforded by the carriage return stop IE]. If the carriage is already in' the returned position there will nevertheless follow the line-spacing operation a fractional space return movement of the carria' eathe carriage falling back into the proper position under control or the escapement as the drive becomes inactive. The carriage return key mences to be power rotated, exerting a pull on the draw band 36.

The line-spacing mechanism 39 and the carriage l afford considerable initial resistance respectively to operation and return and, therefore, the tension on the draw band 3t increases suddenly and violently as the load is being taken up, that is before the line spacing device starts to operate and again before the carriage is picked up. To suppress premature operation of the carriage return shut-off lever tit through the sudden increase of tension on said draw band tending to straighten the stretch of band between the idler sheave 44 and the guide roll E6, there is provided a means comprising a latch l8, see Figure 1, which under carriage control blocks the shut-off lever 66 against operation at all times except when the carriage reaches fully returned position. Said latch i8 is in the form of a lever having a stationary pivot at 80. A member 8| linked to the latch 18 and having a sliding support at 82 in the housing it has a pin-andslot connection at 83 with the arm 2! which has been said to constitute part of a counterstop means. A light spring 84 urges the member 8! leftwardly and thereby causes the arm 2i normally to occupy the left limit in the perforation 22, while maintaining the latch 18 resiliently in the return shut-01f blocking position, all as illustrated in Figure 1. At the very last part of the return movement of the carriage, as illustrated in Figure 3, the margin stop It displaces the arm 25 right wardly and consequently the latch i8 is swung clear of the return shut-off lever lit, 67. Since the resistance of the spring M and the resistance of the latch to movement is light, fiexure of the parts 2|, 8! and i8 is so negligible as not to aifect proper and exact control of the latch l t! by the carriage over a very small movement of the carriage. Thus a fraction of a letter space before the carriage arrives in the fully returned position, the return shut-on lever becomes freed for operation, wherefore then the draw band 36 under the reliable power of the motor drive by a straightening action of the band effectively exerts upward pressure on the pulley 45 to actuate the return shut-off lever (it, 61 clockwise as seen in Figure 3. The roller 68 on the shut-off lever 66, 6'! in such action descends down on the control arm ii) to restore it to open-clutch position, to be held by-the latch t3 if the carriage return key l has meanwhile been released, or

to be held temporarily by a substitute latch 43a seen in Figure 4 if the return hey it is still held operated. The two latches Q3 and 53m are independently pivoted on a common pivot stud, and a spring at connects them resiliently as shown in Figure 4,, in oppositely bearing relation to the pin 16 on the carriage return lever l5. At operation of the latch 43 by the key 115 the latch 43a bears idly rearwardly against the control arm 49 under the tension of the spring 86. When the return shut-off takes place, the control arm 40 receives a power shut-off motion or impulse which carries it far enough for one or the other latch 43, 43a to spring thereover, depending on whether the carriage return key [5 has been released or not, but always when the return shutofi operation has taken place and the return key 6 i5 is released the latch 43 will hold the arm against clutch closure.

It will be evident that at all line-spacing and carriage returning operations the load is icked up with the latch 78 in effective position. Moreover, in view of the latch 18 and the manner of control thereof, the clutch opening action can take place only if the carriage reaches very nearly the return limit position. Because of this the resistance against operation of the shut-ofi lever can be kept to a minimum, and the shut-off action in view thereof takes place with ease, a minimum of strain, friction and shock to the parts. This also reduces noise and the draw band in the embodiment of the invention shown is subjected to a minimum of strain and wear.

The clutch members 25 and ill and the draw band drum 32 with related parts, are contained in a casing, not shown, and from such casing rises upwardly a bracket 8'! which gives support to the pivot pins 59 and 80, as well as to the stop pin 12 and the pulley G4.

The machine of the invention may embody a tabulating mechanism such as shown in the patent to Helmond, No. 2,303,878, dated December 1, 1942 and including a tabulator reed indicated at 88 which upon projection moves slightly right Wardly to a latched position, to be released subsequently for spring restoration by the movement of a tabulator stop thereagainst. If a tabulating run is interrupted by the margin stop I 8 running against and displacing the counterstop 20, then the tabulator reed 88 is unlatched automatically by a pin 96 on the counterstop arm Zil which displaces the reed 88 leftwardly, in a manner conventional in the marketed Underwood All Electric typewriters.

Having explained the nature and objects of the invention, and having specifically described a machine embodying the invention in its preferred form, what is claimed is:

I. In a business machine having a returnable carriage; a normally disabled power-return means for the carriage, means to enable said power-return means, means comprising a part of the power-return means, to tend to disable the powerreturn means after the latter has been enabled, and means including a control element on the carriage to incapacitate said tending means until the carriage in its power return reaches a certain position.

2. In a business machine having a carriage returnable on a frame; a normally disabled powerreturn means for the carriage, means to enable said power-return means, means comprising a part of the power-return means to tend to disable the power-return means after the latter has been enabled, and means to incapacitate said tending means until the carriage in its power return reaches a certain position, said last means comprising an element on the carriage and an element on the frame operable by the first said element as the carriage reaches the said certain position.

3. In a business machine having a returnable carriage and return limiting means for the carriage; normally disabled power-return means for the carriage, means to enable said power-return means, means, comprising a part of said powerreturn means, to tend to disable the power-return means during its enablement, and carriagecontrolled means to incapacitate said tending means until the carriage is power-returned substantially to the limit provided by the said limiting means.

4. In a business machine having a returnable carriage; a member displaced at the conclusion of each return-run of the carriage, normall disabled power-return means for the carriage, means to enable and'to disable saidpower-return means, comprising a part of said power-return means tending to exert a disabling influence on the latter during its enablement, and means controlled by said member to suppress disablement of the power-return means by said tending means in each power-return of the carriage until said member has beendisplaced.

5. In a business machine having a returnable carriage; normally disabled power-return means for the carriage, and means to enable and to disable said power-return means, comprising a device which after enablement of the power-return means is positioned for operation to disable said power-return means, means cooperative with said device and including a part of said powerreturn means to tend, while the latter is enabled, to operate said device, and carriage controlled means to block operation of said device except when the carriage in its return movement reaches a certain position.

6. In a business machine having a returnable carriage and carriage return-limiting means for the carriage; normally disabled power-return means for the carriage, including a carriagereturn draw band, means to enable said powerreturn means, an element arranged for displacement by a straightening pull on said draw band exerted during enablcment of the power-return means, means to disable said poweru'eturn means by the displacement of said element, and car-- riage controlled means to suppress displacement of said element at all times except when the carriage reaches the returned position defined by said return-limiting means.

I. In a business machine having a liinitedly returnable carriage, normally disabled power-return means for the carriage, including a carriage return draw band, means to enable said powerreturn means, an element arranged for displacement by a straightening pull on said draw band exerted during enablement of the power-return means, means to disable said power-return means by the displacement of said element, a member displaced at the conclusion or" the limited return of the carriage, and means controlled by said member to delay operation of said element by said draw band until the carriage reaches the returned position.

8; In a business machine having a returnable carriage; a carriage return drive including a carriage return draw band and a normally open clutch, means to close and to open said clutch, thereby respectively to enable and disable said return drive, said last means including an element associated with the draw band, operable from one to another position to open said clutch, guide means for said draw band arranged relatively to said element for the draw band to exert an impositive power operating force on said operable element while said clutch is closed, and carriage controlled means to block said operable element against operation by said draw band until the carriage in its return movement reaches a certain position.

9. In a business machine having a returnable carriage; a normally disabled power-return drive for said carriage, means to enable and to disable said return drive, comprising, carriage return shut-01f means normally in an idle position, spring means biasing said shut-on means to idle 8. position, means including a control element on the carriage to block said shut-oil means against operation until the carriage in its return run reachesa certain position, and means including a part of the power-return drive tending to poweroperate said return shut-off means in opposition to. said spring whenever said return drive is active wherefore upon arrival of the carriage at said certain position said shut-0d means is automatically power-actuated.

10. The combination with a business machine having a letter-feed carriage, a limitedly operable line-spacing device on the carriage, and carriage returnlimitingmeans including a carriage return limiting margin stop, arranged to permit in any letter-feed position of the carriage short thereof at least some carriage movement in return. direction; of normally disabled power means having aconnection with the line-spacing device to operate it first and then to propel the carriage for return to the limit provided by the return limiting means, and means to enable and to disable said power. means comprising means to tend to disable said power means during enablement thereof, and means controlled by said margin stop to suppress disablement of said power means by said tending means until the carriage after actuation of the line-spacing device has been power propelled substantially to the position defined by the return limiting margin stop, wherefore then the power means is automatically disabled by said tending means.

11. The combination with a business machine having a letter-feedcarriage and a limitedly operable line-spacing device on the carriage; of power means including a motor-operable normally open clutch and a draw band having a connection with said line-spacing device and being operable by said clutch when closed to operate first said line-spacing device and then to propel the carriage in a return direction, and means to open and close said clutch comprising means to tend to open said clutch by a straightening action of said draw band while the clutch is closed, and carriage controlled means to incapacitate said tending means pending the propelling of the carriage in said return direction beyond an initial letter-feed position, the carriage advancing to such position after it has ceased to be propelled in return direction.

12. In a business machine having a returnable carriage and return limiting means for the carriage; a normally disabled power-return drive including a normally open clutch, spring means biasing said clutch to close, releasable latch means normally holding said clutch open in opposition to said spring means, said clutch closing at release of said latch means, means urged by said carriage return drive during activeness thereof to open said clutch in opposition to said spring means, and carriage controlled means to delay operation of said urging means until the powerreturn drive has moved the carriage substantially to a position defined by the return limiting means.

WALTER T. SAGNER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,007,653 LePorin July 9, 1935 2,104,007 Bower Jan. 4, 1938 2,283,565 Michaelsen May 19, 1942 

